| functional reconstitution of membrane proteins in monolayer liposomes from bipolar lipids of sulfolobus acidocaldarius. | membranes of sulfolobus acidocaldarius, an extreme thermophilic archaebacterium, are composed of unusual bipolar lipids. they consist of macrocyclic tetraethers with two polar heads linked by two hydrophobic c40 phytanyl chains which are thought to be arranged as a monolayer in the cytoplasmic membrane. fractionation of a total lipid-extract from s. acidocaldarius yielded a lipid fraction which forms closed and stable unilamellar liposomes in aqueous media. beef heart cytochrome c-oxidase could ... | 1992 | 1309769 |
| action of a cell wall proteinase from lactococcus lactis subsp. cremoris sk11 on bovine alpha s1-casein. | the cell wall-associated proteinase from lactococcus lactis subsp. cremoris sk11 was partially purified and incubated with alpha s1-casein for various times up to 48 h. sixteen trifluoroacetic acid-soluble oligopeptide hydrolysis products were identified by determination of the amino acid sequence. eleven of these oligopeptides originated from the 78-residue sequence comprising the c-terminal region of alpha s1-casein and were present among the products after the first 60 min of digestion. three ... | 1991 | 1367548 |
| effects of nisin on growth of bacteria attached to meat. | nisin had an inhibitory effect on gram-positive bacteria (listeria monocytogenes, staphylococcus aureus, and streptococcus lactis) but did not have an inhibitory effect on gram-negative bacteria (serratia marcescens, salmonella typhimurium, and pseudomonas aeruginosa) attached to meat. nisin delayed bacterial growth on meats which were artificially inoculated with l. monocytogenes or staphylococcus aureus for at least 1 day at room temperature. if the incubation temperature was 5 degrees c, grow ... | 1989 | 2764559 |
| the cytochrome c oxidase test for the rapid detection of psychrotrophic bacteria in milk. | a new, rapid, simple and cheap method for the detection of the predominant psychrotrophic bacteria in raw and pasteurized milks is described, using tetramethyl-p-phenylene-diamine dihydrochloride to detect cytochrome c oxidase which in general is not present in the non-psychrotrophic bacterial milk flora. the test is sensitive to samples containing over 10(4) organisms/ml. correlation coefficients of 0.92 and 0.84 between dye oxidation and viable counts for pasteurized and raw milk samples, resp ... | 1985 | 2995302 |
| herd incidence of bovine mastitis in four danish dairy districts. i. the prevalence and mastitogenic effect of micro-organisms in the mammary glands of cows. | | 1974 | 4213559 |
| antibody response of cows to streptococcus lactis bacteriophage. | | 1970 | 5528757 |
| action of a cell-envelope proteinase (cepiii-type) from lactococcus lactis subsp. cremoris am1 on bovine kappa-casein. | the specificity of the cell-envelope proteinase (cepiii-type) from lactococcus lactis subsp. cremoris am1 in its action on bovine kappa-casein was studied. a 4-h digest (ph 6.2, 15 degrees c) of kappa-casein was made with the purified proteinase. the ph-4.6 soluble fraction, representing more than 95% of the whole hydrolysate, was ultrafiltered to obtain a high-molecular-mass (hmm) and a low-molecular-mass (lmm) fraction, which were separately further purified by electrophoretic and chromatograp ... | 1994 | 7765163 |
| heterologous gene expression of bovine plasmin in lactococcus lactis. | heterologous production of bovine plasmin was studied in the industrially relevant bacterium lactococcus lactis. two sets of lactococcal gene expression signals were coupled to the region of the plasmin gene coding for the serine protease domain. when the promoter region of the prtp gene was used, plasmin was detected mainly intracellularly in strain bpl25 by western blot hybridization. the intracellular presence of plasmin led to physiological stress. expression of the plasmin gene driven by th ... | 1997 | 9352676 |
| heterologous protein secretion in lactococcus lactis: a novel antigen delivery system. | lactic acid bacteria (lab) are gram-positive bacteria and are generally regarded as safe (gras) organisms. therefore, lab could be used for heterologous protein secretion and they are good potential candidates as antigen delivery vehicles. to develop such live vaccines, a better control of protein secretion is required. we developed an efficient secretion system in the model lab, lactococcus lactis. staphylococcal nuclease (nuc) was used as the reporter protein. we first observed that the quanti ... | 1999 | 10347754 |
| effects of the addition of enterococcus faecalis in cebreiro cheese manufacture. | ten batches of cebreiro, a fresh or short-ripened acid-curd cheese, produced in the galician mountains (nw spain) were prepared from pasteurized milk inoculated with microorganisms isolated from raw-milk cheese. two control batches were made with a lactococcus lactis subsp. lactis starter; 8 batches were made with the lactococcal starter plus one of eight enterococcus faecalis cultures: 4 e. faecalis var. liquefaciens (eflb) and 4 e. faecalis var. faecalis (effb). whey dry matter in the eflb was ... | 1999 | 10426446 |
| the effects of cultivating lactic starter cultures with bacteriocin-producing lactic acid bacteria. | the effects of bacteriocins produced by six strains of lactic acid bacteria on 9 mesophilic and 11 thermophilic commercial starter cultures were investigated in mixed cultures of commercial starters with bacteriocin-producing strains in milk. the bacteriocins produced by the test organisms were nisin a, nisin z, lacticin 481, enterocin as-48, a novel enterocin, and a novel plantaricin. mesophilic commercial starters were in most cases tolerant of bacteriocins, with only two of the starters being ... | 2001 | 11198445 |
| bovine rotavirus nonstructural protein 4 produced by lactococcus lactis is antigenic and immunogenic. | rotavirus nonstructural protein 4 (nsp4) can induce diarrhea in mice. to get insight into the biological effects of nsp4, production of large quantities of this protein is necessary. we first tried to produce the protein in escherichia coli, but the nsp4 gene proved to be unstable. the capacity of the generally regarded as safe organism lactococcus lactis to produce nsp4 either intra- or extracellularly was then investigated by using the nisin-controlled expression system. production of recombin ... | 2001 | 11282586 |
| induction of mucosal immune response after intranasal or oral inoculation of mice with lactococcus lactis producing bovine beta-lactoglobulin. | the bovine beta-lactoglobulin (blg) is a major cow's milk allergen. here, we evaluated the immune response against blg induced in mice, using the organism lactococcus lactis, which has gras ("generally regarded as safe") status, as a delivery vehicle. the cdna of the blg gene, encoding blg, was expressed and engineered for either intra- or extracellular expression in l. lactis. using a constitutive promoter, the yield of intracellular recombinant blg (rblg) was about 20 ng per ml of culture. to ... | 2001 | 11329455 |
| lactobacillus bulgaricus proteinase expressed in lactococcus lactis is a powerful carrier for cell wall-associated and secreted bovine beta-lactoglobulin fusion proteins. | lactic acid bacteria have a good potential as agents for the delivery of heterologous proteins to the gastrointestinal mucosa and thus for the reequilibration of inappropriate immune responses to food antigens. bovine beta-lactoglobulin (blg) is considered a major allergen in cow's milk allergy. we have designed recombinant lactococcus lactis expressing either full-length blg or blg-derived octapeptide t6 (idalnenk) as fusions with lactobacillus bulgaricus extracellular proteinase (prtb). in add ... | 2002 | 12039750 |
| free fatty acid accumulation by mesophilic lactic acid bacteria in cold-stored milk. | this study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bacteria (lactococcus lactis subsp. lactis 1471, lactococcus lactis subsp. cremoris 1000 and lactobacillus casei 111) in cold-stored milk. according to the results, all cold-stored milks had higher acid degree values than those of fresh milk. this phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. all lact ... | 2004 | 15357307 |
| evaluation of microbial diversity during the manufacture of fior di latte di agerola, a traditional raw milk pasta-filata cheese of the naples area. | microbial diversity of the raw milk for the production of fior di latte di agerola and its changes during cheesemaking were studied. viable counts showed that at the end of curd ripening, loads of lactic acid bacteria, both mesophilic and thermophilic rods and cocci, higher than those commonly evidenced in similar cheeses produced by using natural or commercial starters, were detected. identification of 272 isolates, supported by molecular diagnostic aids, evidenced representative cultures of a ... | 2006 | 16569276 |
| characterization of dominant microbiota of a ghanaian fermented milk product, nyarmie, by culture- and nonculture-based methods. | to characterize the predominant micro-organisms in a ghanaian traditional fermented dairy product, nyarmie, made from cows' milk, using both culture- and nonculture-based methods. | 2006 | 16696684 |
| human lysozyme expressed in the mammary gland of transgenic dairy goats can inhibit the growth of bacteria that cause mastitis and the cold-spoilage of milk. | the addition of human milk components with intrinsic antimicrobial activity to livestock milk by genetic engineering has the potential to benefit milk safety and production as well as the health of the lactating animal. as a model for the dairy cow, we generated transgenic goats that expressed human lysozyme in their milk at 68% of the levels found in human milk. milk from these transgenic animals had a bacteriostatic effect on both in vitro and in vivo growth of several microorganisms important ... | 2006 | 17199520 |
| influence of the dairy environment on gene expression and substrate utilization in lactic acid bacteria. | lactic acid bacteria (lab) are widely used for the industrial production of fermented dairy products and form a group of related low-gc-content gram-positive bacteria. the major species used in dairy manufacturing are lactobacillus, lactococcus, streptococcus, and leuconostoc. traditionally most are applied as starter cultures for dairy fermentations or used as probiotic cultures, delivered in dairy vehicles. the appearance of the genomes of lactococcus lactis, bidifobacterium longum, lactobacil ... | 2007 | 17311971 |
| efficient production and secretion of bovine beta-lactoglobulin by lactobacillus casei. | lactic acid bacteria (lab) are attractive tools to deliver therapeutic molecules at the mucosal level. the model lab lactococcus lactis has been intensively used to produce and deliver such heterologous proteins. however, compared to recombinant lactococci, lactobacilli offer some advantages such as better survival in the digestive tract and immunomodulatory properties. here, we compared different strategies to optimize the production of bovine beta-lactoglobulin (blg), a major cow's milk allerg ... | 2007 | 17417967 |
| stimulation of nisin production from whey by a mixed culture of lactococcus lactis and saccharomyces cerevisiae. | the production of nisin, a natural food preservative, by lactococcus lactis subsp. lactis (atcc 11454) is associated with the simultaneous formation of lactic acid during fermentation in a whey-based medium. as a result of the low concentration and high separation cost of lactic acid, recovering lactic acid as a product may not be economical, but its removal from the fermentation broth is important because the accumulation of lactic acid inhibits nisin biosynthesis. in this study, lactic acid re ... | 2006 | 18563651 |
| probiotic bacteria affect the composition of salivary pellicle and streptococcal adhesion in vitro. | the use of probiotic bacteria is increasing worldwide and at least some of them can transiently colonize the oral cavity. several studies have shown that probiotic bacteria, which are often thought of in relation only to intestinal health, can also affect the oral ecology, but the mechanisms for this are largely unknown. the aim of this study was to investigate in vitro if the probiotic bacteria used in commercial products affect the protein composition of the salivary pellicle and the adherence ... | 2008 | 18582334 |
| identification of nisin-producing strains by nisin-controlled gene expression system. | a specific method to identify nisin-producing strains was developed based on nisin-controlled gene expression (nice) vector psec:nuc. the plasmid psec:nuc was transformed into non-nisin-producing strain lactococcus lactis nz9000, a host commonly used for the nice system. the generating strain l. lactis nz9000/psec:nuc could sense extracellular inducer nisin and efficiently secrete a reporter protein nuc, the staphylococcal nuclease (nuc) into the medium. instead of using purified nisin, the cult ... | 2009 | 19242754 |
| transfer of antibiotic resistance marker genes between lactic acid bacteria in model rumen and plant environments. | three wild-type dairy isolates of lactic acid bacteria (lab) and one lactococcus lactis control strain were analyzed for their ability to transfer antibiotic resistance determinants (plasmid or transposon located) to two lab recipients using both in vitro methods and in vivo models. in vitro transfer experiments were carried out with the donors and recipients using the filter mating method. in vivo mating examined transfer in two natural environments, a rumen model and an alfalfa sprout model. a ... | 2009 | 19270126 |
| inhibition of uropathogens by lactic acid bacteria isolated from dairy foods and cow's intestine in western nigeria. | a total of 96 lactic acid bacteria (lab) were isolated from african indigenous fermented products and cow's intestines to study their inhibitory capability against multi-drug-resistant uropathogens. escherichia coli accounted for approximately 45% of isolated uropathogens, followed by staphylococcus spp. (20%). the gram negative uropathogens were highly resistant to quinolones, co-trimoxazole, teicoplanin and some beta-lactams, while the staphylococcus spp. showed high resistance to aminoglycosi ... | 2009 | 19529917 |
| inhibition by lactobacillus sakei of other species in the flora of vacuum packaged raw meats during prolonged storage. | the abilities of five lactobacillus sakei strains and one lactococcus lactis strain to retain inhibitory activity against several target organisms in the flora of product during 12 weeks storage of vacuum-packaged lamb and beef was investigated. l. sakei strains were generally found capable of developing dominant populations on both beef and lamb. l. lactis 75 grew poorly on lamb did not inhibit co-inoculated brochothrix thermosphacta. lamb inoculated with the sakacin-a producer l. sakei lb706 h ... | 2009 | 19835775 |
| combined ph and high hydrostatic pressure effects on lactococcus starter cultures and candida spoilage yeasts in a fermented milk test system during cold storage. | the combined effects of high pressure processing (hpp) and ph on the glycolytic and proteolytic activities of lactococcus lactis subsp. lactis, a commonly used cheese starter culture and the outgrowth of spoilage yeasts of candida species were investigated in a fermented milk test system. to prepare the test system, l. lactis subsp. lactis c10 was grown in uht skim milk to a final ph of 4.30 and then additional samples for treatment were prepared by dilution of fermented milk with uht skim milk ... | 2010 | 20832684 |
| study of microbial diversity in raw milk and fresh curd used for fontina cheese production by culture-independent methods. | the bacterial populations of raw milk employed for the production of fontina cheese in alpine farms located in different valleys and altitudes (from 700 to 2246 m above sea level) were investigated by culture independent techniques. total microbial dna was isolated from milk and curd samples and used as template in polymerase chain reaction (pcr) to study the hypervariable v3 region of the bacterial 16s rrna gene and analyzed by denaturing gradient gel electrophoresis (dgge). representative band ... | 2009 | 19232767 |
| biodiversity of lactococcus lactis bacteriophages in the republic of belarus. | we present here the first study on the isolation and characterization of the lactococcal phage content of dairy products from various regions of the republic of belarus. restriction analysis with ecori and hindiii was used to discriminate between isolates. distinct isolates were then further characterized by multiplex pcr analysis and transmission electron microscopy. in total, 23 unique lactococcal phages were isolated. fifteen of them belong to the c2 species, four to the 936 species, and four ... | 2009 | 19195733 |
| antibiotic resistance in lactococcus species from bovine milk: presence of a mutated multidrug transporter mdt(a) gene in susceptible lactococcus garvieae strains. | a total of 72 lactococcus strains (41 lactococcus lactis and 31 lactococcus garvieae) isolated from bovine milk were tested for susceptibility to 17 antibiotics and screened for the presence of antibiotic resistance genes using a microarray. resistance to tetracycline, clindamycin, erythromycin, streptomycin, nitrofurantoin were found. the tetracycline-resistant l. garvieae and l. lactis harbored tet(m) and tet(s). l. lactis that were resistant to clindamycin were also resistant to erythromycin ... | 2008 | 18472369 |
| efficacy of nisin in treatment of clinical mastitis in lactating dairy cows. | nisin is an antimicrobial polypeptide produced by lactococcus lactis and is believed nontoxic to humans. the objective of this study was to evaluate a nisin-based formulation for the treatment of bovine clinical mastitis in lactating dairy cattle. a total of 92 cows with 107 clinically mastitic quarters were randomly assigned to nisin- (48 cows with 51 quarters) and gentamicin (gm)-treated (44 cows with 56 quarters) groups. in the nisin-treated group, cows received an intramammary infusion of ni ... | 2007 | 17639009 |
| intranasal coadministration of live lactococci producing interleukin-12 and a major cow's milk allergen inhibits allergic reaction in mice. | the th1/th2 balance deregulation toward a th2 immune response plays a central role in allergy. we previously demonstrated that administration of recombinant lactococcus lactis strains expressing bovine beta-lactoglobulin (blg), a major cow's milk allergen, partially prevents mice from sensitization. in the present study, we aimed to improve this preventive effect by coadministration of l. lactis blg and a second recombinant l. lactis strain producing biologically active interleukin-12 (il-12). t ... | 2007 | 17202306 |
| evaluation of different preservation techniques on the storage potential of kefir grains. | kefir is an acidic, mildly alcoholic dairy beverage produced by the fermentation of milk with a grain-like starter culture (koroleva, 1988). these grains usually contain a relatively stable and specific balance of microbes that exist in a complex symbiotic relationship (obermann & libudzisz, 1998; witthuhn et al. 2004). the different groups of microbes present in the grains are active at different stages of the fermentation (koroleva, 1982). the lactococci, including lactococcus lactis subsp. la ... | 2005 | 15747741 |
| role of transmembrane ph gradient and membrane binding in nisin pore formation. | nisin is a cationic antimicrobial peptide that belongs to the group of lantibiotics. it is thought to form oligomeric pores in the target membrane by a mechanism that requires the transmembrane electrical potential delta psi and that involves local pertubation of the lipid bilayer structure. here we show that nisin does not form exclusively voltage-dependent pores: even in the absence of a delta psi, nisin is able to dissipate the transmembrane ph gradient (delta ph) in sensitive lactococcus lac ... | 1997 | 8981990 |
| in vitro antimicrobial effect and in vivo preventive and therapeutic effects of partially purified lantibiotic lacticin nk34 against infection by staphylococcus species isolated from bovine mastitis. | lantibiotics are small (<5 kda), polycyclic peptides produced by gram-positive bacteria; they are also known as gram-positive bacteriocins. the high antimicrobial activity of lacticins and the continuing appearance of antibiotic-resistant bacteria in recent years have resulted in a renewed interest in lantibiotics. a partially purified form of lacticin nk34 (a lactococcus lactis product isolated from the korean fermented fish jeotgal) was tested to determine its antimicrobial effects against sta ... | 2010 | 20655430 |